iainjcoleman said:
the words "stop" and "get moving" have no meaning, unless you say "relative to such-and-such an object". You might as well say "You have to elbow purple symphonies".
Sure they do until you get over-technical. When someone says, "Stop the car", everyone knows what is meant without saying, "Stop the car relative to the motion of the street and thus the Earth below it". The car is still moving relative to the Sun, relative to a jet passing overhead, etc. I think if you ask a layperson who hasn't read over this thread what, "Stop your spaceship" means they would not say, "Stop your spaceship relative to the nearest planet, the nearest star, or the center of the galaxy". They would probably just assume you meant to stop any acceleration, shut the engines down after de-accelerating, without actually thinking relative to some fixed object. I can say you are moving 0 MPH and everyone understands that is "not moving" without having to say what it is relative to. Acceleration doesn't need a reference point to make sense, which I think someone already pointed out. If your ship has stopped turning, stopped slowing down, AND stopped speeding up, it is no longer accelerating.
Use the KISS method. Don't think about it too much. That is what I was trying to demonstrate in the fake dialogue above.
Would you prefer this? (added relative motion to the Referee dialogue above):
The Snicker Doodle comes out of jump space at the edge of the empty frontier system to scan for the mysterious mini-black hole reported by the old scout.....
Chris: Let's head to the gas giant first to pick up some fuel before doing any exploring.
Referee: Ok you activate the MD. It will be about a 40 hour trip.
Bob: Let's turn on the SIN sensor to scan for any of those abnormalities the scout reported.
Referee: You have to stop to and power down to use your new SIN sensor.
Chris: We have to stop relative to what fixed object?
Referee: Umm...the gas giant you were headed towards?
Bob: But, the Scout book didn't specify that. We are still moving relative to the local star.
Referee: Ok, you have to stop relative to the star in the system you just arrived in.
Bob: Ok, so if we are lucky we could still be moving towards our target, the gas giant, without any relative motion with the star and thus still able to activate the SIN sensor while making good time?
Chris: But wait, even if we are stopped relative to the star, aren't we still hurtling through space relative to the center of the galaxy? We aren't really stopped, so our SIN sensor still can't work?
Referee: (agitated) The
Snicker Doodle's SIN sensor operating panel suddenly explodes causing D6 damage to everyone nearby. No need to worry about what stop means anymore (makes note to make SIN sensors suddenly a very rare or expensive item).